Is aluminum wiring illegal or does it have to be removed?

Neither. The risk lives at the connections, not the wire runs, and the recognized remedies repair the connections: COPALUM crimps, AlumiConn connectors, or full rewiring where budgets and walls allow.

How do I know if my house has aluminum wiring?

Houses built or expanded roughly 1965 to 1973 are the candidates. Cable jackets in the panel or attic printed AL or ALUMINUM, and silver-colored conductors at accessible junctions, confirm it; an electrician's look settles it.

What are the warning signs of aluminum wiring problems?

Warm cover plates, flickering lights, intermittent dead outlets, buzzing at devices, and burnt-plastic odors, all pointing at deteriorating connections that deserve prompt professional attention.

Does aluminum wiring affect insurance?

Frequently: carriers commonly ask, and may require inspection or approved remediation for coverage. Documentation of COPALUM or AlumiConn repairs is exactly what they want to see.

Is the thick aluminum service cable a problem too?

No. Large-gauge stranded aluminum feeding panels, ranges, and dryers remains standard practice today. The historic problem was small solid-strand branch wiring at 15 and 20 amp circuits.

Aluminum Wiring in Older Homes: Risks and Remedies

Page last reviewed: August 2026 · Reviewed by Harold R. Bennett, retired home inspector

For about eight years, roughly 1965 through 1973, copper prices pushed American builders to wire branch circuits, the everyday 15 and 20 amp outlet and lighting runs, in solid aluminum, and the houses of that era inherited a specific, well-documented problem: not the wire, but its connections. An aluminum wiring house is not a condemned house; it is a house with a known maintenance issue and a short menu of recognized fixes. This reference covers the mechanism, the signs, and the remedies that satisfy both electricians and insurers.

Why the connections fail

Three properties of aluminum conspire at every screw terminal. It expands and contracts with temperature more than copper, so decades of load cycles work terminals loose, a process called creep. Its surface oxide, unlike copper’s, is an electrical insulator, so a loosened joint develops resistance across its oxide film. And resistance at a loose joint makes heat, which accelerates the cycle: heat, expansion, loosening, oxide, more resistance, more heat, the runaway that ends at charred devices and, in the documented worst cases, fires starting at outlets and switches. Add a compatibility wrinkle, early devices whose brass screws and copper-era designs interacted galvanically with aluminum, the same dissimilar-metal chemistry plumbing fights, and the era’s failure statistics wrote themselves. The critical scoping fact: all of this concerns small solid-conductor branch wiring; the fat stranded aluminum cables feeding panels, ranges, and dryers use different alloys and terminations and remain standard, unremarkable practice today.

Identifying and reading the signs

The screening is simple: construction or additions dated to the window, cable jackets printed AL, ALUM, or ALUMINUM visible in the panel, attic, or basement, and silver conductors where junctions are legitimately visible. The symptom list is the connection failure announcing itself: warm or discolored cover plates, flickering lights tied to one area, outlets that work intermittently or die per the dead-outlet patterns, buzzing or crackling at devices, and the unmistakable smell of hot plastic. Any of these in an aluminum-era house moves the timeline from someday to now, and the interim rule is gentleness: heavy plug-in loads, space heaters above all, stress exactly the joints in question.

The recognized remedies

The consensus, shaped by decades of testing and the CPSC’s work on the subject, offers three tiers. Full rewiring in copper retires the issue absolutely and prices accordingly, rational during gut renovations and unbeatable as an endpoint. COPALUM crimping, the gold-standard repair, cold-welds a copper pigtail onto each aluminum conductor with a powered crimp tool, creating a permanent joint at every device and junction; its constraint is the certified-installer network, not the engineering. AlumiConn connectors, the accessible alternative, are set-screw lug connectors rated for the aluminum-to-copper junction, installed at every termination by an electrician at moderate cost, and widely accepted by inspectors and insurers with documentation. What the list pointedly excludes: ordinary twist-on wire nuts, including the purple ones marketed for the purpose, which testing has treated unkindly, and the folk remedy of simply installing CO/ALR-rated devices, which addresses device compatibility but not the junctions elsewhere, a partial measure rather than a remediation. Whichever tier, the deliverable is every connection in the house treated and papers to prove it, the artifact insurers and future buyers both ask for.

Living with it in the meantime

Between discovery and remediation: an electrician’s survey to gauge current condition, AFCI protection added at the panel as a detection net over the arcing failure mode in question, restraint with high-draw plug-ins, and prompt response to any warm plate or flicker. None of that substitutes for the connection work; all of it lowers the odds while the work gets scheduled.

The bottom line

The wire was fine; the connections were the flaw, and the flaw compounds with heat and time. Identify by era and jacket print, read warm plates and flickers as deadlines, remediate with COPALUM or AlumiConn at every junction rather than folklore at a few, and keep the paperwork, because this is the rare house problem with a defined, insurable, permanent fix.